Case report of non-ST-segment elevation myocardial infarction diagnosed in spectral detector-based computed tomography performed for the diagnosis of acute pulmonary embolism

Background Contrast-enhanced spectral detector-based computed tomography (SDCT) allows for the comprehensive and retrospective analysis. We report a case of pulmonary thromboembolism (PE) accompanied by non-ST-segment elevation myocardial infarction (NSTEMI) diagnosed by SDCT. Case summary A 72-year-old man with diabetes mellitus, hypertension, and prostate cancer suddenly developed chest and back pain and had difficulty in breathing at rest. Electrocardiography showed a right bundle branch block without significant ST-segment change. The initial serum troponin I level was 0.05 ng/mL, and the d-dimer level was 14.7 μg/mL. Spectral detector-based computed tomography showed bilateral scattered PE. After admission, his chest pain persisted, and the serum troponin I level 3 h after admission was elevated to 0.90 ng/mL. Reconstruction of SDCT images showed a perfusion defect of the posterolateral left ventricle myocardium. A coronary angiogram showed total occlusion of the obtuse marginal branch (OM); percutaneous coronary intervention was performed. Furthermore, we administered him with oral anticoagulants (OACs) for PE. Spectral detector-based computed tomography tests performed 6 months after the treatment was initiated, until when the dual antiplatelet therapy and OAC therapy were continued, showed improvement in perfusion defects of both pulmonary fields and the myocardium. His treatment was deescalated to single antiplatelet therapy and OAC, and the patient has had a good course. Discussion Non-ST-segment elevation myocardial infarction is sometimes difficult to diagnose accurately, especially in the hyper-acute phase or in the OM branch. The reconstruction of spectral images from enhanced SDCT was helpful to diagnose this unique combination of PE and NSTEMI and may be useful for evaluating therapeutic effects in such patients.